1. Field of the Invention
The present invention relates to a method and a vehicle system for remote-controlling a vehicle audio system controlled in accordance with an instruction from an infrared remote control unit.
2. Description of the Related Art
A conventional vehicle audio system is controllable by operating an operation panel or an infrared remote control unit. FIG. 8 shows the vehicle audio system. Referring to FIG. 8, the vehicle audio system includes a head unit 1, which includes an FM/AM tuner 1a, a CD changer player 1b, and an MD or tape player 1c. A DVD player and/or other sources, e.g., an MP3 player, may also be provided. A source switching unit 2 selects an audio signal to be transmitted from predetermined audio sources in accordance with a switch instruction given by an audio control unit 3, and outputs the selected audio signal to a tone control unit 4. The tone control unit 4 for controlling the tone quality of the input audio signal performs, for example, equalizer control and high/low tone control in accordance with an instruction given by the audio control unit 3. A volume control unit 5 for controlling the volume performs volume control, loudness control, mute on/off control, and the like in accordance with an instruction given by the audio control unit 3. An amplifier 6 amplifies the input audio signal. A speaker 7 emits sound into the interior of a vehicle. An operating unit 8 performs operations such as power on/off, source switching, tone characteristics setting, volume up/down, AM/FM band switching, broadcasting station channel selection, play/stop/pause of the CD player 1b and the MD player 1c, fast-forward/reversing, and tune-forwarding of the CD player 1b and the MD player 1c. Just like the operating unit 8, an infrared remote control unit 9 emits infrared rays to instruct the audio system to perform various operations. The infrared rays are received by a remote control receiver 3a of the audio control unit 3.
The audio control unit 3 performs operations including power on/off control, source switching control, volume up/down control, and play/stop/pause control in accordance with an instruction given by the operating unit 8 or the infrared remote control unit 9.
As described above, the vehicle audio system can be operated by remote control using the infrared remote control unit 9. Although the range of the infrared rays emitted by the infrared remote control unit 9 is short, there is no problem as long as the infrared remote control unit 9 is used in the vehicle.
There are some drivers who enjoy having a picnic outside the vehicle while listening to the music played by the vehicle audio system. In such a case, the vehicle audio system is often required to be operated by remote control. However, the infrared remote control unit 9 having a short range often fails to remotely control the vehicle audio system. The maximum range of the infrared rays emitted by the infrared remote control unit 9 is approximately 25 feet. The range is further shortened due to light effects in the daytime. In addition, it is necessary to operate the infrared remote control unit 9 so that the infrared rays are emitted toward a light receiving section.
Accordingly, it is an object of the present invention to remotely control a vehicle audio system controlled by an instruction from an infrared remote control unit using a radio frequency remote control unit.
It is another object of the present invention to remotely control a vehicle audio system using a radio frequency remote control unit for transmitting a security control command to a security system by radio.
To this end, according to one aspect of the present invention, there is provided a method for remotely controlling a vehicle audio system, including a transmitting step of transmitting an audio control command for controlling the audio system by a high-frequency wireless signal; a demodulating step of demodulating the audio control command sent by the wireless signal; and an outputting step of outputting an infrared remote control signal based on the audio control command.
In the method, a radio frequency remote control unit of a vehicle security system may give an instruction to switch a control mode between an audio control mode and a security control mode. When mode switching is instructed and the control mode is switched to the audio control mode, the audio control command received from the radio frequency remote control unit may be converted into an infrared remote control unit command thereafter.
According to another aspect of the present invention, there is provided a vehicle system including an audio system which is remotely controlled by infrared rays; an infrared emitter for generating the infrared rays; a security system for receiving a command transmitted from a radio frequency remote control unit, performing security control in a security control mode based on the command (security command), and externally outputting the command transmitted from the radio frequency remote control unit as an audio control command in an audio control mode; and an audio control interface unit, connected to the security system, for converting the audio control command output from the security system into an infrared remote control unit command, and driving the infrared emitter based on the command.
According to the present invention, the audio system can be externally operated by remote control without hindrance. It is not necessary to provide an additional radio frequency remote control unit for controlling the audio system. With the audio control interface unit and the infrared emitter, the audio system can be operated by remote control using the radio frequency remote control unit.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings.